U.S. patent number 5,526,066 [Application Number 07/943,227] was granted by the patent office on 1996-06-11 for picture display device.
This patent grant is currently assigned to Sony Corporation. Invention is credited to Toshihiro Kikuchi.
United States Patent |
5,526,066 |
Kikuchi |
June 11, 1996 |
Picture display device
Abstract
A picture display device which displays either of two pictures
having different aspect ratios on the same screen thereof includes
two screening units and a filter member which is disposed ahead of
the screening units. Each screening unit has a rotatable reel and a
screening sheet which is wound around the reel. The screening sheet
is movable by the rotation of the reel so as to fully expose a
screen of the picture display device and to screen a remaining or
no-signal portion of the screen.
Inventors: |
Kikuchi; Toshihiro (Saitama,
JP) |
Assignee: |
Sony Corporation (Tokyo,
JP)
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Family
ID: |
17483560 |
Appl.
No.: |
07/943,227 |
Filed: |
September 10, 1992 |
Foreign Application Priority Data
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Sep 20, 1991 [JP] |
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3-270244 |
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Current U.S.
Class: |
348/841;
348/E5.111; 348/E5.131 |
Current CPC
Class: |
H04N
5/65 (20130101); H04N 7/0122 (20130101) |
Current International
Class: |
H04N
5/65 (20060101); H04N 5/44 (20060101); H04N
005/65 () |
Field of
Search: |
;348/836,841,844 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2104073 |
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Apr 1990 |
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JP |
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2179085 |
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Jul 1990 |
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JP |
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2189085 |
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Jul 1990 |
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JP |
|
Primary Examiner: Ro; Bentsu
Attorney, Agent or Firm: Kananen; Ronald P.
Claims
What is claimed is:
1. A picture display device which is capable of displaying either
of first and second pictures having first and second aspect ratios
respectively on a screen thereof, the screen having the first
aspect ratio, said device comprising:
a housing;
a filter member for covering the screen, said filter member being
connected to said housing; and
a screening unit for screening a remaining portion of the screen,
the remaining portion being produced when the second picture is
displayed on the screen, said screening unit including:
a reel which is rotatably, connected to said housing;
a screening sheet which is wound around said reel; and
drive means to rotate said reel in a certain direction so as to
move said screening sheet, from a first position in which the
screen is fully exposed so as to display the first picture thereon,
to a second position in which the remaining portion is screened by
said screening sheet, said filter member being positioned so as to
cover said screening unit.
2. A picture display device according to claim 1, wherein said
drive means comprises a DC motor.
3. A picture display according to claim 1, wherein said screening
unit further comprises a pinch roller which is positioned away from
said reel such that said screening sheet is interposed between the
pinch roller and said reel, and wherein the pinch roller is so
arranged as to rotate in an interlocking manner in a direction
which is opposite to that of the rotation of said reel, thereby
smoothly moving said screening sheet.
4. A picture display device according to claim 1, wherein said
screening unit further comprises a first switch for stopping the
rotation of said reel when said screening sheet takes the second
position and a second switch for stopping the rotation of said reel
when said screening sheet takes the first position.
5. A picture display device according to claim 1, wherein said
screening unit is mounted in a frame which is detachably mounted on
said housing.
6. A covering device for covering a nonilluminated portion a TV
picture tube, said covering device comprising:
a housing;
a filter member for covering a screen of the picture tube, said
filter member being connected to said housing; and
a screening unit for screening a nonilluminated portion of the
screen, the nonilluminated portion being produced when a
partial-screen picture is displayed on the screen, said screening
unit including:
a reel which is rotatably connected to said housing;
a screening sheet which is wound around said reel; and
drive means to rotate said reel in a certain direction so as to
move said screening sheet, from a first position in which the
screen is fully exposed so as to display a full-screen picture
thereon;
to a second position in which the nonilluminated portion is
screened by said screening sheet, said filter member being
positioned so as to cover said screening unit.
7. A covering device according to claim 6, wherein said drive means
comprises a DC motor.
8. A covering device according to claim 6, wherein said screening
unit further comprises a pinch roller which is positioned away from
said reel such that said screening sheet is interposed between the
pinch roller and said reel, and wherein the pinch roller is so
arranged as to rotate in an interlocking manner in a direction
which is opposite to that of the rotation of said reel, thereby
smoothly moving said screening sheet.
9. A covering device according to claim 6, wherein said screening
unit further comprises a first switch for stopping the rotation of
said reel when said screening sheet takes the second position and a
second switch for stopping the rotation of said reel when said
screening sheet takes the first position.
10. A covering device according to claim 6, wherein said screening
unit is mounted on a frame which is detachably mounted on said
housing.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a picture display
device such as a television receiver, and more particularly to a
picture display device which displays either of two pictures having
different aspect ratios on the same screen thereof.
2. Description of the Prior Art
A standard television receiver displays on a screen thereof a
picture of which aspect ratio is 4 to 3. On the other hand, a high
definition television receiver displays on a screen thereof a
picture of which aspect ratio is 16 to 9. That is, the ratio of
horizontal width of the picture to vertical height thereof in
television is 16:9.
Thus, as is seen from FIG. 9, in case that a high definition
picture having the aspect ratio of 16:9 is displayed on a standard
television screen having the aspect ratio of 4:3, there are
produced two remaining portions or no-signal portions 10 on the
upper and lower end portions of the screen. Thus, the remaining
portions 10 have no picture thereon.
On the other hand as is seen from FIG. 8, in case that a standard
picture having the aspect ratio of 4:3 is displayed on a high
definition television screen having the aspect ratio of 16:9, there
are produced two remaining portions 12 on the two side portions of
the screen.
As is mentioned hereinabove, the remaining portions are produced by
the difference between the aspect ratio of the picture and that of
the screen. The remaining portions make the screen unsightly when
the picture is displayed on the screen.
In view of this, there are proposed display devices, for example,
Japanese Patent First Publications Hei-2-104073, Hei-2-179085 and
Hei-2-189085, each of which is equipped with two movable screening
members to cover or screen the remaining portions of the television
screen. However, these conventional display devices equipped with
the movable screening members have the following drawbacks.
The movable screening members which are mounted on a front portion
of a TV housing are exposed and thus within a TV viewer's reach.
Therefore, the movable screening members are necessarily made of
plastic or the like which is high in rigidity so as not to be
damaged even if the TV viewer adds a substantially large force to
the movable screening members. Furthermore, the television receiver
is to be necessarily equipped with a safety device to automatically
stop the movement of the screening members when the TV viewer
touches the screening members by mistake. Thus, the structure of a
drive unit to move the screening members complicated due to the
installation of the safety device thereon.
The above-mentioned conventional screening members are platelike in
shaped slidable in a vertical or horizontal direction so as to move
from a first position in which the TV screen is fully exposed to a
second position in which the remaining portions of the TV screen
are screened thereby. Thus, o a relatively large space must be
provided for the sliding movement of the screening members. This
tends to impede the development or of a compact TV set.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an
improved picture display device in which a safety device to
automatically stop the movement of screening members can be
omitted.
It is another object of the present invention to provide a picture
display device of which screening members can be received in a
relatively small space.
It is still another object of the present invention to provide a
picture display device of which screening members are not within a
TV viewer's reach.
According to the present invention, there is provided a picture
display device which is capable of displaying either of first and
second pictures having first and second aspect ratios respectively
on a screen thereof, the screen having the first aspect ratio, the
device comprising: a housing; a filter member for covering the
screen, the filter member being connected to the housing; and a
screening unit for screening a remaining portion of the screen, the
remaining portion being produced when the second picture is
displayed on the screen, the screening unit including: a reel which
is rotatably connected to the housing; a screening sheet which is
wound around the reel; and drive means to rotate the reel in a
certain direction so as to move the screening sheet, from a first
position in which the screen is fully exposed so as to display the
first picture thereon, to a second position in which the remaining
portion is screened by the screening sheet, the filter member being
positioned so as to cover the screening unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a high definition television
receiver which is equipped with two screening units according to
the present invention;
FIG. 2 is a perspective and schematic view of a front portion of
the high definition television receiver, showing a condition in
which two movable screening sheets are respectively fully wound
around reels;
FIG. 3 is a view similar to FIG. 2, but showing a condition in
which the movable screening sheets are unwound from the reels so as
to screen two side retaining portions of a screen of the high
definition television receiver;
FIG. 4 is a front elevational view of the high definition
television receiver which is equipped with a front frame on which
the screening units are mounted;
FIG. 5 is a side elevational view of the front frame; showing the
front frame on which the screening unit is to be
FIG. 6 is an enlarged rear perspective and exploded view,
mounted;
FIG. 7 is a graph in which reflectance of a filter member of the
present invention as a function of wavelength solid line (a) and in
which transmittances of the filter member and a conventional
untreated filter member as a function of wavelength are
respectively shown by solid lines (b) and a chain line (c);
FIG. 8 is a perspective view of a rear projector-type high
definition television receiver which is equipped with two screening
units according to the present invention; and
FIG. 9 is a perspective view of a rear-projector type standard
television receiver which is equipped with two screening units
according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 to 6, there is provided a direct viewing type
high definition television receiver (DV-HDTV) which is equipped
with two screening units according to the present invention.
As is seen from FIG. 1, DV-HDTV has a direct viewing tube 14
disposed in a housing 13 thereof. The direct viewing tube 14 has a
screen of which aspect ratio is 16:9. Therefore, a high definition
picture of which aspect ratio is 16:9 can be displayed on the
screen without having a remaining or no-signal portion thereon.
When a standard picture of which aspect ratio is 4:3 is displayed
on the screen of DV-HDTV, there are inevitably produced the
remaining portions 16 on two side portions of the screen.
Accordingly, in accordance with the present invention, the
screening units are provided so as to screen the remaining portions
16 upon displaying the standard picture. Since the two screening
units are identical in construction, only one screen unit will be
described in the following.
As is seen from FIGS. 4 and 5, each screening unit is mounted on a
front frame 17. The front frame 17 is rectangular in shape and
detachably mounted on a front portion of the housing 13.
As is seen from FIGS. 2 and 3, each screening unit has a screening
sheet 18 which is a plastic sheet or the like. The screening sheet
18 is wound around a reel 20 which is rotatably mounted on the
front frame 17. The screening sheet 18 is horizontally movable by
the rotation of the reel 20, from a first position in which the
screening sheet 18 is substantially fully wound around the reel 20
so as to fully expose the screen (see FIG. 2), to a second position
in which the screening sheet 18 is unwound from the reel 20 so as
to screen the remaining portion 16 of the screen (see FIG 3).
As is seen from FIG. 6, the reel 20 is rotated by a DC motor 22
which is received in a case 24. The screening unit has a pinch
roller 26 which is rotatable with the reel 20 in an interlocking
manner through gears 28 and 30. The pinch roller 26 is so
positioned away from the reel 20 such that the screening sheet 18
is interposed between the pinch roller 26 and the reel 20.
Furthermore, the pinch roller 26 is so arranged by the gears 28 and
30 such that the pinch roller 26 is rotated in a direction opposite
to that of the reel 20, as is shown by arrows of FIG. 6. Therefore,
the screening sheet 18 is smoothly wound around the reel 20 and
unwound therefrom. The screening sheet 18 has a leading edge which
is vertically defined and reinforced by a reinforcing member 32 so
as to have a certain shape upon winding and unwinding the screening
sheet 18. The reel 20 is covered by a protective cover 34.
Designated by numeral 36 is a filter member which also serves as a
protective cover of the screen. The filter member 36 is disposed
ahead of the screening sheets 18 and mounted on a front end surface
of the front frame 17, such that the screening units can not be
touched by a TV viewer by mistake. The filter member 36 is made of
a transparent glass plate or a transparent plastic plate or the
like a predetermined thickness, for example, 3 mm. The filter
member 36 is reinforced and treated so as to have a high
transmittance and a low reflectance substantially throughout tile
visible portion of the spectrum, as is shown in FIG. 7. Thus,
undesirable reflectance of the outside light can be suppressed by
the filter member 36.
Operation of the screening unit according to the present invention
will be describe in the following.
The description will be commenced on the assumption that the
screening sheet 18 takes the above-mentioned first position in
which it is substantially wound around the reel 20. Under this
condition, the screen of which aspect ratio is 16:9 is fully
exposed so as to display the high definition picture thereon.
When the standard picture is to be displayed on the screen, the
reel 20 is rotated by the DC motor 22 so as to unwind the screening
sheet 18 arid to screen the remaining portion 16 of the screen by
the same. When the screening sheet 18 is moved to the
above-mentioned second position in which the remaining portion 16
is fully screened by the screening sheet 18, the position of a
leading edge of the screening sheet is detected by a first position
sensing leaf switch 38 so as to stop the movement of the DC motor
22 and the reel 20.
When the high definition picture is to be displayed again on the
screen, the reel 20 is rotated by the DC motor 22 so as to wind the
screening sheet 18 around the reel 20 and to fully expose the
screen. When the screening sheet 18 is moved to the first position,
the position of the leading edge of the screening sheet 18 is
detected by a second position sensing leaf switch 40 so as to stop
the movement of the DC motor 22 and the screening sheet
Referring to FIG. 8, there is provided a rear projector type high
definition television receiver (RP-HDTV) which is equipped s with
the two screening units according to the present invention. The
screening units are disposed beside two side end portions of a
screen of RP-HDTV, and have screening sheets 18 which are
horizontally movable. RP-HDTV has a filter member 36 which is
disposed ahead of the screening units.
Referring to FIG. 9, there is provided a rear projector type
standard television receiver (RP-SDTV) which is equipped with the
two screening units according to the present invention. The
screening units are disposed next to upper and lower end portions
of a screen of RP-SDTV, and have screening sheets 18 which are
vertically movable. RP-SDTV has a filter member 36 which is
disposed ahead of the screening units.
Advantages of the picture display device according to the present
invention will be described in the following.
Since the picture display device has the filter member 36 which is
disposed ahead, ad of the screening units, the screening s units
can not be touched by a TV viewer by mistake. Therefore, a safety
device to automatically stop the movement of the screening sheets
can be omitted, and thus the structure of the screening units can
be simplified.
When the screening sheet is not used for screening the remaining
portion of the screen, it is substantially fully wound around the
reel. Thus, it takes a relatively small space.
* * * * *